Hurricanes, Weather and other things – Jay Hobgood's Web site and blog

Ernesto Makes Transition to Tropical Storm

Former Subtropical Storm Ernesto made a transition to a tropical storm on Thursday afternoon. At 5:00 p.m. EDT on Thursday the center of Tropical Storm Ernesto was located at latitude 43.0°N and longitude 41.0°W which put it about 645 miles (1035 km) east-southeast of Cape Race, Newfoundland. Ernesto was moving toward the northeast at 18 m.p.h. (30 km/h). The maximum sustained wind speed was 45 m.p.h. (75 km/h) and there were wind gusts to 60 m.p.h. (95 km/h). The minimum surface pressure was 1007 mb.

Even though now Tropical Storm Ernesto moved over water where the Sea Surface Temperature was between 24°C and 25°C, there was enough energy in the upper ocean to cause more thunderstorms to develop. In addition, many of the thunderstorms developed close to the center of circulation. The inner bands of showers and thunderstorms became stronger and the bands in the outer parts of the circulation weakened. Ernesto exhibited a structure like a tropical cyclone and the National Hurricane Center classified the system as a tropical storm in the 5:00 p.m. EDT advisory.

Tropical Storm Ernesto will move over much cooler water during the next 24 hours. It is likely to make a transition to an extratropical cyclone when it moves over the cooler water. Ernesto could strengthen when colder air is pulled into the western half of the circulation and a cold front forms south of the center. The development of the cold front and upper level divergence could strengthen the pressure gradient force which would give the air a stronger push. An upper level trough east of the U.S. is forecast to steer Ernesto in the general direction of Ireland and the United Kingdom.